1. Field of the Invention
This invention relates to a camera having a light press timer.
2. Related Background Art
In an ordinary AE camera, when a release button is operated (half-depressed) to a predetermined position short of the release position, a light press switch is closed, whereby a light metering circuit in the camera is operated to detect the luminance of an object to be photographed. There is also known a camera in which an exposure value (such as an aperture value or a shutter speed) calculated on the basis of the luminance of the object to be photographed is displayed on a liquid crystal display device or the like, for example, through a display circuit. The light press timer is one which maintains the power source until a predetermined power source maintaining time (e.g. 8 seconds) elapses even if the half depression operation is thereafter released and the light press switch is opened. Accordingly, even after the release of the half depression, the display of the exposure value is continuedly effected for a predetermined time and therefore, this is convenient when manually adjusting the aperture value or the shutter speed (adjusting the exposure) while watching, for example, the exposure value.
However, if the above-mentioned power source maintaining time is set to a short time, the timer is switched off to extinguish the display before the exposure adjustment is completed and therefore, the half depression operation must be performed again, and this means poor usability. So, if the power source maintaining time is made uniformly long, the above-noted problem will be solved, but in this case, there is still the problem that even after photographing or after photographing is discontinued due to a variation in the luminance of the object to be photographed, the power source is unnecessarily maintained and the battery is wastefully consumed.